1. Field of the Invention
The invention relates to a cell culture device the culture surface of which is coated with at least one of ε-poly-L-lysine, further polymerized derivatives of ε-poly-L-lysine and their salts.
2. Technical Background
Devices for the culture of adhesive cells including Petri dishes and chambers, the culture surface of which is coated with a cationic polymer such as α-polylysine or polyethylenimine, to enhance cell adhesion, are generally known (as disclosed e.g. in Patent Ref. 1) and commercially available. Coating materials with higher biocompatibility, such as chitosan, are also under development. Such devices are relatively inexpensive and easy to manufacture, such that they are widely used for primary culture and subculture of adhesive cells, including fibroblasts, smooth muscle cells, blood vessel endothelial cells and corneal cells, as well as floating cells such as blood cells.
However, cationic polymers such as α-polylysine or polyethylenimine are known to have a relatively high cytotoxicity. In addition, although some kinds of cells can grow on such a device, insufficient adhesion or poor development of the cytoskeleton are often observed, particularly in primary cultures. In order to improve adhesion and growth, some commercially available cell culture devices have the culture surface coated with extracellular matrices such as collagen or gelatin, or with biomaterials such as fibronectin, laminin or vitronectin (see e.g. general Ref. 1).
These biomaterials are, however, generally expensive and their method of coating involves cumbersome processes. The stability of the coated surface is also unsatisfactory, presenting problems during storage. An improved culture method is therefore much needed allowing the simple and inexpensive coating of a cell culture surface that possesses low cytotoxicity and which also exhibits effective cell expansion and growth, as well as offering favorable cell morphology and arrangement.
The above Patent Reference 1 is JP-A-H06-181740, and General Reference 1 is Mochizuki, M., Kadoya, Y., Wakabayashi, Y., Kato, K., Okazaki, I., Yamada, M., Sato, T., Sakairi, N., Nishi, N., and Nomizu, M., FASEB J., 17, 875-877 (2003).